Fabric wrap



United States Patent FABRIC WRAP Raymond H. Pestell, Old Hickory, Tenn., assignor to E. I. du Pont de Nemours and Company, Wilmington, DeL, a corporation of Delaware Application September 29, 1953, Serial No. 382,970

3 Claims. (Cl. 20659) This invention relates to a fabric wrapping material and to the processing of yarn in the form of annular cakes, such as are produced in the rayon industry, concerning particularly a knit wrap for covering yarn cakes.

A rotating bucket is an accepted means for collecting yarn produced by the viscose rayon process. Freshly made yarn fed into the bucket collects against the internal wall, accumulating to a suitable depth to form what is called a cake, which may be removed as such from the bucket for further processing. Besides bleaching and purification, which customarily are accomplished at the manufacturing plant, the cake may undergo additional processing, such as dyeing, there or elsewhere before the yarn is unwound from it.

During processing in cake form, the component yarn should not become broken, disarranged, or snarled because any disturbance of the yarn enrollment will hinder the unwinding that necessarily precedes actual use of the yarn. The cake should also remain clean and free from contamination with undesirable substances that it may contact during handling and shipping. Some cover or wrap for the cake is required for adequate protection against soilage and entangling, which put part of the yarn to waste whenever they occur.

A successful wrap for yarn cakes will hold the yarn firmly enough to prevent disarrangement but will stretch enough to facilitate wrapping and unwrapping, will cover the cake sufficiently to protect the surface without being an obstacle to uniform flow of processing liquids through the wrap and into the cake, and will be light in weight and inexpensive. Conventional knit wraps are either heavy and expensive or weak and sleazy. Paper wraps are not resilient enough to hold the outside yarns of a cake in place; furthermore, papers thin enough to be readily permeable are not sturdy enough to stand up well under the impact of handling and processing.

A primary object of this invention is construction of a fabric ideally suited as a cover or wrap for yarn cakes to protect them during handling, processing, and shipping. A particular object of this invention is provision of a fabric wrap containing yarn made of continuous filaments and yarn made of staple fiber, with the staple yarn predominating in a raised pattern on one face of the fabric. Also an object is the wrapping of yarn cakes with a knit fabric ribbed with staple yarn so as to interlock overlapping portions of the wrap firmly in place when on a yarn cake. Another object is construction of a resilient nonraveling knit wrap for yarn cakes. A further object is provision of an effective knit wrap that can be discarded economically after a single use. Means and methods for accomplishing the above and other objects will be apparent from the following discussion and the accompanying diagrams.

Figure l is a view of the flat face of a wrap fabric of this invention showing the stitch construction. Figure 2 is a view of the same wrap from the opposite, or ribbed, face of the fabric. Fig. 2A is a view of the fabric of Figure 2 in extended or as-knit condition. Figure 3 ICC is an enlarged edge view of the fabric taken on line 3-3 in Figure 1. Figure 4 is a sectional view of a yarn cake covered by a fabric wrap of this invention.

In general, the objects of this invention are accomplished by a combination of rib knitting of staple yarn with flat knitting of yarn composed of continuous filaments. Production on acircular knitting machine is most convenient, as the wrap is used in tubular form. The following example illustrates the preparation and application of a particular knit wrap according to this invention.

Example A ribber having a diameter of 4% inches is prepared for operation with a full complement of 150 cylinder needles and with only dial needles of like gauge. An end of rayon staple yarn equivalent in weight to 30/1 cotton count is fed to both cylinder and dial needles, as in ordinary rib knitting, while an end of 40-filament rayon yarn totaling denier is fed only to the cylinder needles, as in ordinary flat knitting, about a half cycle away from the other feed point. Tension and stitch are regulated to consume 3.0 lbs. staple yarn for every 2.0 lbs. continuous filament in producing 530 ft. of tubing (measured in relaxed or tension-free condition). The finished tubing is capable of stretching flat to a double-thickness Width of about 12 inches without permanent distortion. Figure 1 shows the smooth unribbed face of a single layer of the tubing; this is the outside as the fabric is knit, and it is the side used to contact the yarn cake. Figure 2 shows the ribbed face of the fabric; and Figure 3 is an end view, which shows even more clearly the protrusion of loops to constitute ribbing R. In these drawings, the staple yarn appears light and the continuous filaments appear dark to render them .easily distinguishable. The smooth face of the tubing atits normal width exhibits about 8-10 Wales and 18 to 24 courses per inch; the other face shows 9 to 12 double-length loops of staple yarn per inch in each rib. The stitch construction is apparent from the diagrams, in which the fabric appears expanded widthwise for clarity of the showing and to suggest extension of the fabric as on a cake. When cut into tubular lengths this fabric does not unravel freely; thus, unlike the usual fabric wrap made with a plain or jersey unit, its ends need not be altered in stitch or bound mechanically. In wrapping, a length of 29 inches of this tubing, weighing slightly over /a ounce, is passed axially inside a cake of rayon yarn having an inside diameter of about 4 /2 inches, an average outside diameter of about 6% inches and an over-all height of about 4 inches. (This cake weighs about 3 pounds when wet, approximately one pound dry.) The opposite ends of the tubing are folded, successively outward and over the cake, one end being covered by the other, as shown in Figure 4. Thus, the inside of the cake is protected by a single layer and the outside by a double layer of wrap, the cake itself being contacted by the smooth face of the fabric, while the ribbed surface of the inside layer lodges against the opposite face of the outside layer so as to stabilize the position of the wrap. With this selected length of wrap the outside end extends beyond the top of the cake, so, for convenience, it is tied 05 in a figure-of-eight knot. This wrap proves highly satisfactory in protecting the cake during all conventional handling, processing, and shipping.

A yarn cake wrapped according to this invention is benefited by the light, yet firm, cling of the wrap to the surface of the cake. The presence of continuous filaments and staple yarn throughout contributes uniform high strength and resilience. No staple yarn protrudes from the smooth side of the wrap to snag the cake, but the staple ribbing on the outside of the inner layer of wrap provides a strong frictional gripping elfect against the outer layer of Wrap, tending to distort it enough between locations underneath the outer ribbing to prevent slippage of one layer over the other. This construction is an evident advance over existing all-staple fabrics which entangle with the surface yarns of the cake; fabrics composed wholly of continuous filaments, which are slippery and less resilient; and possible simple combinations of the two. A Well-known conventional type of Wrap is a plain knit tubing of continuous filaments With end bands of staple yarn; the wrap of the present invention weighs not more than /3 as much and is obviously much less expensive to manufacture, among other advantages.

The Wrap of the above example is suitable as a cover for smaller and for somewhat larger cakes of yarn. Larger cakes may be accommodated also by wraps similarly constructed on machines of larger diameter, such as 5, 6, or more inches or alternatively, may be formed of similar materials on a machine of the same diameter as in the example but equipped with more needles, e. g. 85

dial and 170 cylinder needles, or with a greater disproportion in the number of needles. The size of the yarns used may be varied as required, suitable ranges being 50 to 300 denier continuous filament and staple yarn of from 76/ 1 to 26/ 1 count, which is equivalent to from about 70 to 200 denier. Of course, plied yarns may be used. The weight ratio of staple to continuous filament may vary somewhat from that of the example. The exposed end of the wrap may be secured in any satisfactory manner, as by knotting, pinning, sewing, or tying; under mild conditions it may be left loose. The rib construction may be modified, if desired.

Other kinds of fiber may be employed in the manufac ture of knit wraps according to this invention. Thus,

cotton is satisfactory for the staple yarn, while any of a wide variety of man-made polymeric materials, e. g., polyamide, polyester, or polyvinyl compounds, may make up either one of the component yarns. Of course, rayon is a highly economical choice, especially in the rayon industry itself. The wraps may be used to cover bobbins and other articles besides yarn cakes where similar protection is required.

What is claimed:

1. Rib-knit wrap fabric containing both continuousfilament yarn and staple-fiber yarn and having ribbed wales of staple yarn separated from one another by plural-ities of plain wales of the two types of yarn interknit with one another.

2. Package comprising an annular yarn cake wrapped in a tubing of the fabric of claim 1 with the tubing enfolding the entire surface of the cake, the ribs of the fabric facing away from the cake surface and the ends of the tubing overlapping one another.

3. The package of claim 2 in which the overlapping of the ends of the fabric tubing extends over the entire peripheral surface of the annular yarn cake.

References Cited in the file of this patent UNITED STATES PATENTS 391,005 Munsing Oct. 9, 1888 2,214,021 Hill Sept. 10, 1940 2,230,067 Pedlow Jan. 28, 1941 2,608,078 Anderson Aug. 26, 1952 FOREIGN PATENTS 283,304 Great Britain Jan. 12, 1928 

